Trimming knives

ABSTRACT

A trimming knife is disclosed having an elongate body which is tapered from a rounded wider end to a narrower end and which has an end face. A coiled tape measure is housed within the rounded wider end of the elongate body, which has an end portion extendable from a slot formed in the end face. A flashlight is housed in the elongate body and arranged to show from the end face and illuminate the tape measure when the tape measure is extended from the slot. Finally, a blade, or a socket for mounting said blade, is provided in the end face so that a cutting edge of the blade extends alongside and at the level of the tape measure when the tape measure is extended from the slot.

This invention relates to improvements in trimming knives.

A trimming knife comprises generally speaking a handle and a replaceableblade, and may be used among other operations for cutting hard-board,plaster-board and other panels. In carrying out such an operation, it isusually necessary to first use a rule or tape measure and pencil to markout a cutting line, and then use a straight edge placed along thecutting line to guide the trimming knife in actually making the cut.This involves the provision of at least four different implements (rule,pencil, straight edge [which may or may not be the rule], and knife).Furthermore, if working in poor light, as in an attic, cellar, or spacein a building under construction not yet provided with lighting, a thirdhand is required to hold a torch.

An object of this invention is to enable all or most of these functionsto be achieved by using a single tool.

In accordance with the invention, therefore, a trimming knife isprovided which has a handle into which is embodied at least anextendable and retractable tape measure.

This measure is preferably extendable and retractable via an orificeadjacent a blade, or a socket for fitting a blade.

The knife handle further preferably has a built-in flashlight positionedto illuminate the area around the blade or blade holding socket.

The handle may enclose a compartment for replacement blades.

Separate finger-operable switches may be provided, one each forextending and/or retracting the blade, locking or unlocking the tapemeasure, and/or operating the flashlight.

A preferred embodiment of improved trimming knife according to theinvention will now be described, by way of example, with reference tothe accompanying drawings, wherein:

FIG. 1 is a partially sectional side elevation of a trimming knifeaccording to the invention;

FIG. 2 is a view of the blade end face of the trimming knife; and

FIG. 3 is a view of the outside casing of the trimming knife.

An improved trimming knife 10 according to the invention includes ahandle 11, which is advantageously profiled to be a comfortable fit in auser's hand.

The handle has a narrow end 12 in which is provided a blade-holdingsocket for a replaceable cutting blade 13. The handle additionallyaccommodates an extendable and re-windable tape measure 14, with a tang15 which prevents it from being retracted within the end 12.

In addition, the handle accommodates a flashlight, comprising a small,e.g. 1.25 volt, 250 milli-amp bulb 16 mounted in the end 12 to directlight into the space around the blade 13.

A battery 17, e.g. a 1.5 volt widely obtainable pencil battery LR1battery is mounted in a space aligned with the bulb 16, and can be movedby a light switch 18 to contact the end of the bulb 16. The circuit iscompleted by a coil spring 19, one end of which is wrapped about thebulb 16 and the other end having a tail which, when the battery is moveddown into contact with the bulb, contacts the rear face of the battery17.

A sliding switch 20 is provided to extend and retract the blade 13, inknown manner, and a further finger lever 21 is provided to lock orunlock the tape 14 for extension and retraction.

A pencil 23 with an eraser tip 24 is received in a bore in the handle,adjacent and parallel to the flashlight. As shown in FIG. 3, a panel 25of white plastics material, which can be marked by the pencil, andcleaned by the eraser, is provided on one side of the handle, forjotting notes.

In use, the tape 14 may be used first to define a cut-line, then serveas a straight edge for guiding the cutting blade 13 thereby removing thenecessity for a separate straight-edge, rule, pencil and trimming knifenormally used for cutting materials such as plasterboard, cardboard,hardboard etc. All four operations can be carried out by the improvedtrimming knife tool. The flashlight may be used to illuminate the areaabout the blade 13, to allow working in darkened areas. A compartment 22in the butt 23 of the handle 11 is provided to accommodate replacementblades 13.

What is claimed is:
 1. A trimming knife, comprising:an elongate bodybeing tapered from a rounded wider end to a narrower end having an endface; a coiled tape measure being housed within said rounded wider endand having an end portion extendable from a slot formed in said endface; a flashlight being housed in said body and arranged to show fromsaid end face and illuminate said tape measure when said tape measure isextended from said slot; and, a blade, or a socket for mounting saidblade, provided in said end face so that a cutting edge of said bladeextends alongside and at the level of said tape measure when said tapemeasure is extended from said slot.
 2. The trimming knife according toclaim 1, wherein said elongate body encloses a compartment forreplacement blades.
 3. The trimming knife according to claim 1, furthercomprising separate finger-operable switches for extending or retractingsaid blade.
 4. The trimming knife according to claim 1, furthercomprising separate finger-operable switches for locking or unlockingsaid tape measure.
 5. The trimming knife according to claim 1, furthercomprising separate finger-operable switches for operating saidflashlight.
 6. The trimming knife according to claim 7, furthercomprising a pencil with an eraser received in a bore in said end face,adjacent and parallel to said flashlight.
 7. The trimming knifeaccording to claim 6, further comprising a panel being mounted onto theexterior of said elongate body, said panel being able to be marked bythe pencil, and cleaned by the eraser, for jotting notes.